When mounting various electrically operating instruments such as speedometer, temperature indicator and radio receiver on an instrument panel of a motor vehicle, it is ideal that the setting of the electric instruments in a predetermined position on the panel simultaneously completes its mechanical mounting and necessary electrical connections or wiring.
According to one conventional practice, the wires to be connected to sensors and lamps on the instrument panel are led out of the engine room through the dash lower panel and collected to a junction block, which is located beneath the instrument panel, and then distributed to the respective instruments by means of a number of separate connecting wires or a wire harness or cable assembly binding up a necessary number of connecting wires. The leading ends of the connecting wires are connected to terminal elements of one mating member which is fixed on the panel and which is matingly engageable with another mating member on the part of the electric instruments when the latter are set in position on the panel.
This manner of wiring using separate connecting wires between the junction block and the respective electric instruments is confusing and complicated since a large number of wires jumble together behind the instrument panel or within a limited space between the instrument panel and the vehicle body. On the other hand, the cable assembly makes rattling noises by hitting against the instrument panel or other nearby parts due to mechanical vibrations of the vehicle.